The postulated glass-liquid transition of low density amorphous ice (LDA) is investigated with deuteron NMR stimulated echo experiments. Such experiments give access to ultra-slow reorientations of water molecules on time scales expected for structural relaxation of glass formers close to the glass-liquid transition temperature. An involved data analysis is necessary to account for signal contr...

We show that finite-size scaling techniques can be employed to study the glass transition. Our results follow from the postulate of a diverging dynamical correlation length at the glass transition whose physical manifestation is the presence of dynamical heterogeneities. We introduce a parameter B(T,L) whose temperature, T, and system size, L, dependences permit a precise location of the glass ...

The problems posed by glass are not only practical but also conceptual: despite the progress afforded by advances in glass science, we still lack a complete understanding of how a liquid becomes a glass. Indeed, in contrast to most phase transitions, many measureable physical and chemical glass properties change smoothly across the liquid-to-glass transition at the glass transition temperature ...

Many liquids have heat capacities that substantially exceed those of the corresponding crystal, and this discrepancy magnifies in the supercooled regime. Thus, liquid entropy declines more rapidly with temperature than does crystal entropy, and the former paradoxically seems to fall below the latter for temperatures below the Kauzmann point TK • Although laboratory glass transitions inevitably ...

The origin of the β transition in poly(vinylidene fluoride) (PVDF) is still a pending question. This transition has been studied by dynamic mechanical analysis (d.m.a.) and differential scanning calorimetry (d.s.c.) in dependence on sample annealing and dilution with e-caprolactam (CPL). The β transition temperature is increased upon annealing and thus influenced by the polymer crystallization....

The nanophase separation in diblock and triblock copolymers consisting of immiscible poly(n butyl acrylate) (block A) and gradient copolymers of methyl methacrylate (MMA) and n butyl acrylate (n BA) (block M/A) were investigated by means of their heat capacity, Cp, as a function of the composition of the blocks M/A and temperature. In all copolymers studied, both blocks are represented by their...

Theoretical computation of the pressure dependence superconducting state parameters of binary Ca60Al40 is reported using model potential formalism. Explicit expressions have been derived for the volume dependence of the electron–phonon coupling strength λ and the Coulomb pseudopotential μ* considering the variation of Fermi momentum KF and Debye temperature ӨD with volume. Well known Ashcroft’s...

Silica (SiO2) glass, an essential material in human civilization, possesses excellent formability near its glass-transition temperature (Tg > 1100 °C). However, bulk SiO2 glass is very brittle at room temperature. Here we show a surprising brittle-to-ductile transition of SiO2 glass nanofibers at room temperature as its diameter reduces below 18 nm, accompanied by ultrahigh fracture strength. L...